Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

I have here a piston connecting rod that has just a little too much play in the bearing/bushing that connects it to the shaft.  Is there a bearing/bushing that can be replaced or does the whole connecting rod/shaft assembly need to be replaced? This is off of a Honda 5hp horizontal shaft 4 stroke engine that belongs in a honda single stage snowblower (HS520). 

How bad are the scratches on the bore and crank journal?  As someone on this list once wrote, “can your run your fingernail across the journal and not catch it on bumps and ruts?   If there are no ruts you might get lucky and be able to sand off minor high spots and remain within spec.  You’d have to be very lucky. 

 

   The same for the bore.  Are they scratches or surface marks?   They look bad but again if you were lucky and no ruts then you could re-hone and see how close you are to tolerance limits.  How do you check?  HF sells a bore gauge set for $7. They have a digital vernier for $10 on sale.  The gauge compares well to a much more expensive Starett.

 

   The idea being it might be worth the $50 to get an education.  Rebuild the motor and see how it comes out.  You might get lucky on the first shot.  People on the list helped me out and my first motor actually ran well.  If it runs and sucks as a motor you’ll have made a big accomplishment.  It would be better to hack on this motor as a learning experience then learn on a much more valuable engine. 

 

   Harbor Freight has some decent engines.  I bought three last week at $109 each.  They come with a 90 day warrantee.  For 11 bucks they add 12 months so that will cover these motors over two snow seasons.  The warrantee is also transferable.  The HF motors are made in China by Lifan.  Lifan is one of China’s better makers of small engines.  They are a giant company making all sorts of motorized things.  I know their motorcycles very well and they are excellent.

 

   The HF engine is 6.5hp, OHV, cast iron bore, and low oil shutoff protection, arm throttle control but has holes for a cable, fuel shutoff and choke at the carb.  They are made in partnership with Honda so a legal clone and the parts interchangeable with Honda.  I have mounted a few on great older Ariens bodies. 

 

   One of these engines might be an option.  Lifan is a quality maker but who knows the actually quality of the model HF is selling. ?? We’ll see.  I spent 4 years in China and pretty familiar with their small motors so getting them was not a problem for me.

 

   If you did replace yours I’d still go with the rebuild if the scoring was not prohibitive.  Even just putting it all back together would be worthwhile.  It’s not as complicated as it seems once you wade in.

David

trouts2 wrote:

A finger nail does not snag on any of the scratches. The scatches on the piston and cylinder  are more like surface wear marks. The crank shaft is smooth as glass but darker in color.   My camera does not allow me to get much depth of field with the flash on. That's why the photos are so blurry on the cylinder.
I realize that I'm the only one that can really see/touch the damage. So I'm really the only one in a position to do a fair job of assessing the damage. Infortunately I have no knowledge of what I'm looking at.

I have a 15% coupon to harbor freight and they have a store near me.  I'm not sure how difficult it would be to size another engine to fit (even a honda clone).  I could take the old engine with me to the store and set them side by side.  This being a single stage blower everthing needs to fit inside a plastic housing.  That might also mean the end to the electric start and who knows what else.

As for putting it together.  I found an exploded diagram of the engine so i might be able to get it back together.  The shop manual would probably be a neccessity. Would I at the very least want to replace the old connecting rod ($20 delivered)?  I would need to find some way to clean everything really well. Not sure how I would do that.  There are small piece of grit everywhere from it sitting under the tree. (the owner was leaving it out for the rubbish).

 I would have more confidence/faith in fixing the engine if I had a better idea of why it failed.  Give the benifit of the doubt to the person that set it up before it left the showroom. It was full of oil.  In 3 years on a 14 foot driveway (I saw the driveway and the owner was as honest/respectable/conscientios as they come).  Say 16 storms a year, 30 minutes/storm, 3 years = 24 hours (total).  I cannot figure out what went wrong or why the plastic cam wheel would have broken. 

I think I'll sleep on it.

I would put it back together and see how it ran,  I think someone took it too a shop.   They gave him a high est. and he took i back home apart...there is not much carbon on the piston,  The pictures I  see refer to grit in the engine.  I bet there was not much wrong with this motor as far as running... Shops sometimes will not put something back together after an estimate is preformed without work...   Out of spite they take it apart and HOPE the guy leaves it at the shop for parts in leu of fee...

I must have rebuilt 200 engines over  the years,  I see nothing that would keep a good honda from running, It looks like someone never changed the oil.... It probly had a stuck valve and/  or a gunked up carb...

Put it back together with the parts that are there,  run it on the bench to see if it is usable....  If it runs ok,   then think about how much money to throw into it...

I live and work in the desert... You give a Honda to a illegal  and let and he will do this to the motor in a matter of months,   but it will still run fine for years at 4-6 hours a day...

Friiy

I agree 100%. This isnt an aircraft engine that is used in a critical situation. I dont see any major issues and it will be a great learning experience.  Try your public library for a book on small engine repair a similar Honda engine may be discussed.  Make it a fun project and take your time.  Just make a point of getting as much of the grit out of it as possible especially around the rings and grooves.  I have used Simple Green as a soaking solution on my BMW pistons (81 bike with 152,000 miles and runs great!)
Packo

If Underdog wants to do if for the experience, I agree, go ahead a put it together.  However, I wouldn't put a dime into it.  Doing a fingernail drag around the scored cylinder doesn't let you know if it's out of round.  From the wear pattern on the cylinder and piston, you can pretty much bet that it is.  I'm certain that the engine will run but it will burn oil, be noisy (for a Honda), and will also be low on power.   I'd put it back together nonetheless just to see how long it would last in that condition.  I repeat that I just wouldn't put money into it. 

When I buy Honda products, I make sure I get the "GX"  engine.  It's a bit more expensive but it will outlast a GC many times over if properly maintained.  These B&S snow engines are not much different than the Honda GC series engines.  No iron cylinder sleeve.  I wasn't too concerned with that aspect because the B&S engine I have is on a snow thrower.  Cool operating temps and clean environment will help to extend it's life.  If it does blow, I'd certainly make sure I replace it with an IC series or better yet, a suitable B&S Vanguard which is made in Japan.  

So, go ahead.  Put it together and keep let us know how it runs. 

Being an over head cam engine, you'll have to make sure you have the timing gears properly aligned.   There should be indicators on both gears and the manual should also tell you what position they should be in.    

PACKO wrote:

Thanks for all the input on this decision.  So I slept on it  last night and I think I have a plan:

I'll  start shopping around for a replacement engine.  See what's out there, what it would cost, and how well it would fit.

Meanwhile,  I'll  toss everything in a vat of "simple green" and hose it down. Then I'll  find a shop manual (I might even be able to resell the manual when I'm done with it) and spread all the parts out on the dining room table (a nice warm well lit room) .  After the baby goes to bed I'll spend a few minutes each night and see if  I can figure it out.